BOSTON, MA (NBC) A recent study showed that athletes who began playing tackle football before the age of twelve, could be faced with problems later in life.
Those issues include mood swings, emotional problems and depression.
Dr. Robert Stern is a leading researcher with Boston University and says, "This study showed starting tackle football before age 12 seems to increase the risk for later life problems."
They found repetitive head impacts-not concussions-before age 12 doubles the risk of behavioral problems such as moodiness and apathy, and triples the chance of suffering depression later in life.
Doctors say age 10-12 is a key time for boys still developing brains.
They found the younger the players are when starting tackle football, the greater risk of those problems later in life.
Dr. Stern says, "Every time the body or the head gets hit and the head moves quickly-the brain gets sheared and stretched."
Dr. Stern says, "It's not those big hits and having symptoms and diagnosed with concussion. We are talking about the many hits per game and per practice without feeling anything from it."
Pop Warner, the youth football organization, issued this statement to NBC Boston Investigators regarding the Boston University study:
"The participants in this study played youth football 40 years ago. Youth football has evolved significantly since that period and the major changes Pop Warner has implemented have revolutionized the sport, making it safer and better than ever before. It has been suggested that selection bias calls into question the conclusions of this study. Still, our medical advisory committee will review it and compare it against the number of recent studies that contradict these findings. The greatest evidence against this study may be the millions of successful individuals who played youth football and went on to become leaders in society as teachers, doctors, police officers, business owners, CEOs, judges and journalists."
For the study, the researchers looked at 214 former football players who began before age 12 and played only through high school or college. The average age of the study participant was 51.